The overall objective of the proposed research is to elucidate the physiological roles of sperm metalloproteases in reproduction. Most of the emphasis will be placed on investigations with Pz-peptidase B. Pz-peptidase will be purified from bovine sperm extracts using chromatographic techniques. The purified Pz-peptidase B will be characterized with respect to its physicochemical and biochemical properties. Particular attention will be given to determining the cleavage specificity of Pz-peptidas B using various peptide and protein substrates. Purified Pz-peptidase B will be used to immunize rabbits for production of specific anti-Pz-peptidase B antibodies. Immunoglobulins purified form the resulting antisera will be employed to establish the subcellular location of Pz-peptidase B in bovine spermatozoa by immunocytochemical techniques. The possible participation of Pz-peptidase B in sperm penetration of wvum investments will be investigated by determining the ability of this matalloendopeptidase to dissolve the zona pellucida and evaluating the effect of specific Pz-peptidase B inhibitors on sperm penetration on ova in vitro. The potential role of Pz-peptidase B in activation of proacrosin and regulation of physiologically active peptides such as enkephalins will also be examined. In related studies, Pz-peptidase A will be isolated from bovine spermatozoa and biochemically characterized. The similarity of Pz-peptidase A to dipeptidyl carboxypeptidase and the potential physiological role of this matalloprotease in regulation of bioactive peptides such as angiotensin and bradykinin will be investigated. The results of these studies will contribute to basic knowledge in reproductive biology and may find practical appplication in development of improved methods for human fertility regulation.